[cr0sh]

That's pretty much also why they'll never open source VB6, despite a very large number of developers wanting it.

Instead, Microsoft has been virtually forced to continue to include the VB runtime DLL in every version of Windows since, because there are so many businesses out there that rely on software developed in VB6 that can't (easily or cheaply) switch to something else.

Windows 10, from what I understand, almost became the first version to ship without it, but Microsoft relented under the pressure (maybe I'm misinformed here, though).

VB.NET is sufficiently different enough that conversion either isn't possible, or due to the source code not being available (or the 3rd-party company that wrote it not existing any longer as an entity - or the source code assets not available or whatnot due to dissolution) - conversion becomes nearly impossible, short of a very expensive reverse-engineering effort by another 3rd party.